Oh Man!
I don't even have my fish yet, but I just saw two small (1.5 cm?), skinny white worms crawling on the inside of my tank! Is this common? I can't imagine its good. I do have 2 plants and a moss ball in there, perhaps the worms snuck in with them.

Any and all advice welcome. I'm about 9 days into cycling the tank, so I'd like to not have to start over if possible.

Also- if you are familiar with these little worms, is it anything that can be transferred to humans?

The worms could be nematodes. I got them through a couple of guppies, and they killed off all the fish in my tank. There are different types and not all are parasitic but its best not to chance it (and yes they can come on plants!)
There is a sort product to kill them, so check at an aquarium store but its not always available.
But if you cant find that I think its safest to clean out your tank :/

Otter- I haven't been feeding at all- I don't even have a fish yet. :( still cycling (with ammonia and Dr. Tim's One and Only).
I have been doing water changes as I cycle, but I haven't been actually vacuuming the gravel because I wanted to preserve the bacteria. I think now, I start getting into the gravel. Do you think that will slow the cycle?

My ammonia is staying 0 each night (and I add in a few drops after testing), but my nitrites are really high. Between 2 and 5 (honestly- I can't tell the difference) every night. So I've been doing a 2gal (out of 5 g) water change.

Otter- I haven't been feeding at all- I don't even have a fish yet. :( still cycling (with ammonia and Dr. Tim's One and Only).
I have been doing water changes as I cycle, but I haven't been actually vacuuming the gravel because I wanted to preserve the bacteria. I think now, I start getting into the gravel. Do you think that will slow the cycle?I do not believe vacuuming will remove the BB.
Then the worms might come from your plants. I suppose if there is a lack of food, it will die off.

So if this is a fishless cycle, are you using a dead shrimp or just ammonia chemical?

My ammonia is staying 0 each night (and I add in a few drops after testing), but my nitrites are really high. Between 2 and 5 (honestly- I can't tell the difference) every night. So I've been doing a 2gal (out of 5 g) water change.

((PS- are you the same Otterfun from HCA forum?))

Oh, what is HCA? Apparently it is a nice enough name for someone to use it

I'm using ammonia drops from Dr. Tim's.
Last night was the first night that my ammonia wasn't 0. Does that make any sense to anyone? That it would go up? Nitrites starting to go down, also nitrates are starting to go down.

Now I'm worried that maybe there are dead worms in my filter and they are causing the ammonia to go up. eeeeeeyyyyyywwwwwwwwwww.

((HCA is the hermit crab association. I'm a huge otter fan myself so I shouldn't be surprised there is more than one out there ;) :)

If they're crawling on the glass, they're either detritus worms or planaria. Detritus worms have round heads, planaria heads are sort of triangular. Either way, they'll make a nice snack for the fish once you add them. Nematodes, planaria, and detritus worms are not parasitic. Planaria may attack sick shrimp or any type of fry, but for full-grown fish they're nothing more than a quick treat. Nematodes are generally free-swimming, so these don't appear to be that.

I like to catch the planaria in my shrimp tank with tweezers and drop them to the bettas for a snack. I'm about to kill off the planaria from the shrimp tank, though ... since I don't have fish they think they run the place!